ERA began as a group working on code-breaking for the U.S. Navy during WWII. After the war their leader, William Norris, was encouraged to set up a commercial firm to continue this work.

ERA produced a number of very early machines for the Navy and other government agencies. Commercial versions of these machines were produced later.

In 1952, ERA was purchased by Remington Rand (later Sperry Rand) who had earlier also purchased the Eckert-Mauchly Computer Corporation. The two firms became the Univac Division of Sperry Rand. Norris and a number of other employees left to form Control Data Corporation.

Several Rand employees purchased the ERA name in the late 1970s and founded a consulting firm. It had a short existence and today is part of the Raytheon Corporation.